# Psychology 3800F/G Lecture Notes - Lecture 1: Chi-Squared Test, Statistical Parameter, Random Assignment

## Document Summary

4:18 pm focus more on the conceptual aspects of what the tests are doing. Why invest in quantitative methods theoretical inquiry systematic empirical work of science testing hypotheses description and classification developing models methods can help formulate research questions applied inquiry evaluation (ie. program or rct) assessment and diagnosis describing a population prediction. Histogram right/positively skewed distribution (the way the tail goes is how you name it) measure of central tendency: mean, median, mode. Standard scores z-score mean = 0; sd = 1 provides indication of relative standing in distribution. **distribution of sample means is normal regardless of skew of sample data** Confidence intervals gives estimated range of values which is likely to include an unknown population parameter, the estimated range being calculated from a given set of sample data. "i am ____% confident that the true population mean lies within this set of values" the more confident you want to be, the wider your range has to be.